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Nov 6, 2018
11/18

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J. N. BARBOSA BOCAGE

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This paper is in the public domain in USA. Metadata comes from the CrossRef API, see full record in the source URL below.

Topic: journals

Source: https://api.crossref.org/works/10.1038/016061d0

"Rank Among States not Determined by Their Military Standing" is an article from The Advocate of Peace (1894-1920), Volume 70 . View more articles from The Advocate of Peace (1894-1920) . View this article on JSTOR . View this article's JSTOR metadata . You may also retrieve all of this items metadata in JSON at the following URL: https://archive.org/metadata/jstor-20665436

Source: http://www.jstor.org/stable/10.2307/20665436

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Sep 17, 2013
09/13

by
Valmir C. Barbosa

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We introduce the notion of a network's conduciveness, a probabilistically interpretable measure of how the network's structure allows it to be conducive to roaming agents, in certain conditions, from one portion of the network to another. We exemplify its use through an application to the two problems in combinatorial optimization that, given an undirected graph, ask that its so-called chromatic and independence numbers be found. Though NP-hard, when solved on sequences of expanding random...

Source: http://arxiv.org/abs/1003.1412v1

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Sep 20, 2013
09/13

by
Geraldo A. Barbosa

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This work shows how a secure Internet for users A and B can be implemented through a fast key distribution system that uses physical noise to encrypt information transmitted in deterministic form. Starting from a shared secret random sequence between them, long sequences of fresh random bits can be shared in a secure way and not involving a third party. The shared decrypted random bits -encrypted by noise at the source- are subsequently utilized for one-time-pad data encryption. The physical...

Source: http://arxiv.org/abs/quant-ph/0607093v2

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Sep 21, 2013
09/13

by
Valmir C. Barbosa

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We study the growth of networks from a set of isolated ground nodes by the addition of one new node per time step and also of a fixed number of directed edges leading from the new node to randomly selected nodes already in the network. A fixed-width time window is used so that, in general, only nodes that entered the network within the latest window may receive new incoming edges. The resulting directed network is acyclic at all times and allows some of the ground nodes, then called sinks, to...

Source: http://arxiv.org/abs/0706.3805v1

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Sep 21, 2013
09/13

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Gregory Leighton; Denilson Barbosa

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The eXtensible Markup Language (XML) provides a powerful and flexible means of encoding and exchanging data. As it turns out, its main advantage as an encoding format (namely, its requirement that all open and close markup tags are present and properly balanced) yield also one of its main disadvantages: verbosity. XML-conscious compression techniques seek to overcome this drawback. Many of these techniques first separate XML structure from the document content, and then compress each...

Source: http://arxiv.org/abs/0905.4761v1

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Sep 22, 2013
09/13

by
V. C. Barbosa

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We discuss general models of resource-sharing computations, with emphasis on the combinatorial structures and concepts that underlie the various deadlock models that have been proposed, the design of algorithms and deadlock-handling policies, and concurrency issues. These structures are mostly graph-theoretic in nature, or partially ordered sets for the establishment of priorities among processes and acquisition orders on resources. We also discuss graph-coloring concepts as they relate to...

Source: http://arxiv.org/abs/cs/0309044v1

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Sep 22, 2013
09/13

by
V. C. Barbosa

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For $k\ge 1$, we consider interleaved $k$-tuple colorings of the nodes of a graph, that is, assignments of $k$ distinct natural numbers to each node in such a way that nodes that are connected by an edge receive numbers that are strictly alternating between them with respect to the relation $

Source: http://arxiv.org/abs/math/0309380v1

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Sep 18, 2013
09/13

by
G. D. Barbosa

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We study the conditions for spontaneous symmetry breaking of the (2+1)-dimensional noncommutative phi^6 model in the small-theta limit. In this regime, considering the model as a cutoff theory, it is reasonable to assume translational invariance as a property of the vacuum state and study the conditions for spontaneous symmetry breaking by an effective potential analysis. An investigation of up to the two loop level reveals that noncommutative effects can modify drastically the shape of the...

Source: http://arxiv.org/abs/hep-th/0306064v3

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Sep 18, 2013
09/13

by
Geraldo A. Barbosa

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This work shows how two parties A and B can securely share sequences of random bits at optical speeds. A and B possess true-random physical sources and exchange random bits by using a random sequence received to cipher the following one to be sent. A starting shared secret key is used and the method can be described as an unlimited one-time-pad extender. It is demonstrated that the minimum probability of error in signal determination by the eavesdropper can be set arbitrarily close to the pure...

Source: http://arxiv.org/abs/quant-ph/0212033v4

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Sep 18, 2013
09/13

by
Geraldo A. Barbosa

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One-time pad encrypted files can be sent through Internet channels using current Internet protocols. However, the need for renewing shared secret keys make this method unpractical. This work shows how users can use a fast physical random generator based on fluctuations of a light field and the Internet channel to directly boost key renewals. The transmitted signals are deterministic but carries imprinted noise that cannot be eliminated by the attacker. Thus, a one-time pad for Internet can be...

Source: http://arxiv.org/abs/0704.1484v1

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Sep 23, 2013
09/13

by
Aline Mauricio Barbosa

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We study the existence and uniqueness problem of compact minimal vertical graphs in H^n x R, n greater than or equal to 2, over bounded domains in the slice H^n x {0}, with non-connected boundary having a finite number of C^0 hypersufaces homeomorphic to the sphere S^{n-1}, with prescribed bounded continuous boundary data, under hypotheses relating those data and the geometry of the boundary. We show the nonexistence of compact minimal vertical graphs in H^n x R having the boundary in two...

Source: http://arxiv.org/abs/1303.3089v2

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Sep 21, 2013
09/13

by
Geraldo A. Barbosa

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Coincidence-structures in the transverse plane of Type-II spontaneous parametric down-conversion carrying orbital angular momentum are obtained. Azimuthal symmetry breaking around the pump beam direction reveals itself on these quantum images. Analytical expressions for the amplitude probability of the down conversion process are shown including the nonlinear polarizability components.

Source: http://arxiv.org/abs/0706.0894v1

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Sep 21, 2013
09/13

by
Valmir C. Barbosa

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Given two subsets A and B of nodes in a directed graph, the conduciveness of the graph from A to B is the ratio representing how many of the edges outgoing from nodes in A are incoming to nodes in B. When the graph's nodes stand for the possible solutions to certain problems of combinatorial optimization, choosing its edges appropriately has been shown to lead to conduciveness properties that provide useful insight into the performance of algorithms to solve those problems. Here we study the...

Source: http://arxiv.org/abs/1204.6181v1

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Sep 20, 2013
09/13

by
G. Dourado Barbosa

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We propose an alternative interpretation for the meaning of noncommutativity of the string-inspired field theories and quantum mechanics. Arguments are presented to show that the noncommutativity generated in the stringy context should be assumed to be only between the particle coordinate observables, and not of the spacetime coordinates. Some implications of this fact for noncomutative field theories and quantum mechanics are discussed. In particular, a consistent interpretation is given for...

Source: http://arxiv.org/abs/hep-th/0301106v3

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Sep 23, 2013
09/13

by
G. D. Barbosa

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We study the implications of a noncommutative geometry of the minisuperspace variables for the FRW universe with a conformally coupled scalar field. The investigation is carried out by means of a comparative study of the universe evolution in four different scenarios: classical commutative, classical noncommutative, quantum commutative, and quantum noncommutative, the last two employing the Bohmian formalism of quantum trajectories. The role of noncommutativity is discussed by drawing a...

Source: http://arxiv.org/abs/hep-th/0408071v2

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Oct 28, 2014
10/14

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Barbosa, Susana; Hastings, Ian M

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This article is from Malaria Journal , volume 11 . Abstract Background: Insecticides are an effective and practical tool for reducing malaria transmission but the development of resistance to the insecticides can potentially compromise controls efforts. In this study a mathematical model was developed to explore the effects on mosquito populations of spatial heterogeneous deployment of insecticides. This model was used to identify important parameters in the evolution of insecticide resistance...

Source: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3557165

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Jun 27, 2018
06/18

by
Frédéric Maffray; Artur Mesquita Barbosa

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A b-coloring of a graph $G$ is a coloring of its vertices such that every color class contains a vertex that has neighbors in all other classes. The b-chromatic number of $G$ is the largest integer $k$ such that $G$ has a b-coloring with $k$ colors. Javadi and Omoomi ("On b-coloring of cartesian product of graphs", Ars Combinatoria 107 (2012) 521-536) proved that the b-chromatic number of $K_n \times K_n$ (the Cartesian product of two complete graphs on $n$ vertices) is in the set...

Topics: Combinatorics, Mathematics

Source: http://arxiv.org/abs/1504.01975

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Jun 26, 2018
06/18

by
Leonardo S. Barbosa; Nestor Caticha

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We study source localization from high dimensional M/EEG data by extending a multiscale method based on Entropic inference devised to increase the spatial resolution of inverse problems. This method is used to construct informative prior distributions in a manner inspired in the context of fMRI (Amaral et al 2004). We construct a set of renormalized lattices that approximate the cortex region where the source activity is located and address the related problem of defining the relevant variables...

Topics: Quantitative Biology, Neurons and Cognition, Quantitative Methods

Source: http://arxiv.org/abs/1502.03481

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Sep 17, 2013
09/13

by
R. Aldrovandi; A. L. Barbosa

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The cosmological constant Lambda, which has seemingly dominated the primaeval Universe evolution and to which recent data attribute a significant present-time value, is shown to have an algebraic content: it is essentially an eigenvalue of a Casimir invariant of the Lorentz group which acts on every tangent space. This is found in the context of de Sitter spacetimes but, as every spacetime is a 4-manifold with Minkowski tangent spaces, the result suggests the existence of a "skeleton"...

Source: http://arxiv.org/abs/gr-qc/0207044v2

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Jul 20, 2013
07/13

by
Andreas Doering; Rui Soares Barbosa

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The so-called topos approach provides a radical reformulation of quantum theory. Structurally, quantum theory in the topos formulation is very similar to classical physics. There is a state object, analogous to the state space of a classical system, and a quantity-value object, generalising the real numbers. Physical quantities are maps from the state object to the quantity-value object -- hence the `values' of physical quantities are not just real numbers in this formalism. Rather, they are...

Source: http://arxiv.org/abs/1107.1083v1

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Sep 21, 2013
09/13

by
Ezequiel R. Barbosa; Marcos Montenegro

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We develop a comprehensive study on sharp potential type Riemannian Sobolev inequalities of order 2 by means of a local geometric Sobolev inequality of same kind and suitable De Giorgi-Nash-Moser estimates. In particular we discuss questions like continuous dependence of optimal constants and existence and compactness of extremal maps. The main obstacle arising in the present setting lies at fairly weak conditions of regularity assumed on potential functions.

Source: http://arxiv.org/abs/1011.1037v2

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Jul 20, 2013
07/13

by
Edilson Vargas; Marcia C. Barbosa

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We consider here a blend made of two types of polymers, $A$ and $B$, of different chemical nature. At high temperature the homogeneous mixture is cross-linked. As the temperature is lowered, the two species try to segregate but are kept together by the cross-links. We show that for inhomogeneous, non-regular and non-permanent cross-links, there is a complete segregation at low temperatures if the system is just weakly cross-linked and partial segregation, otherwise. We also demonstrate that...

Source: http://arxiv.org/abs/cond-mat/9712212v1

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Sep 22, 2013
09/13

by
Charles H. Lineweaver; Domingos Barbosa

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Recent cosmic microwave background (CMB) measurements over a large range of angular scales have become sensitive enough to provide interesting constraints on cosmological parameters within a restricted class of models. We use the CMB measurements to study inflation-based, cold dark matter (CDM) critical density universes. We explore the 4-dimensional parameter space having as free parameters, Hubble's constant Ho, baryonic fraction Omega_b, the spectral slope of scalar perturbations n and the...

Source: http://arxiv.org/abs/astro-ph/9612146v2

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Sep 19, 2013
09/13

by
Ezequiel R. Barbosa; Marcos Montenegro

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We concerns here with the continuity on the geometry of the second Riemannian L^p-Sobolev best constant B_0(p,g) associated to the AB program. Precisely, for 1

Source: http://arxiv.org/abs/0708.2376v2

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Sep 22, 2013
09/13

by
Andre Nathan; Valmir C. Barbosa

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When a neuron fires and the resulting action potential travels down its axon toward other neurons' dendrites, the effect on each of those neurons is mediated by the weight of the synapse that separates it from the firing neuron. This weight, in turn, is affected by the postsynaptic neuron's response through a mechanism that is thought to underlie important processes such as learning and memory. Although of difficult quantification, cortical synaptic weights have been found to obey a long-tailed...

Source: http://arxiv.org/abs/0906.3252v1

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Sep 21, 2013
09/13

by
Elias Bareinboim; Valmir C. Barbosa

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The load of a node in a network is the total traffic going through it when every node pair sustains a uniform bidirectional traffic between them on shortest paths. We show that nodal load can be expressed in terms of the more elementary notion of a node's descents in breadth-first-search (BFS or shortest-path) trees, and study both the descent and nodal-load distributions in the case of scale-free networks. Our treatment is both semi-analytical (combining a generating-function formalism with...

Source: http://arxiv.org/abs/0712.3924v1

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Jul 20, 2013
07/13

by
P. P. Avelino; D. Barbosa

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We consider a model for the reionization history of the Universe in which a significant fraction of the observed optical depth is a result of direct reionization by the decay products of a scaling cosmic defect network. We show that such network can make a significant contribution to the reionization history of the Universe even if its energy density is very small (the defect energy density has to be greater than about $10^{-11}$ of the background density). We compute the Cosmic Microwave...

Source: http://arxiv.org/abs/astro-ph/0406063v1

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Sep 23, 2013
09/13

by
Andre Nathan; Valmir C. Barbosa

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An information-theoretic framework known as integrated information theory (IIT) has been introduced recently for the study of the emergence of consciousness in the brain [D. Balduzzi and G. Tononi, PLoS Comput. Biol. 4, e1000091 (2008)]. IIT purports that this phenomenon is to be equated with the generation of information by the brain surpassing the information which the brain's constituents already generate independently of one another. IIT is not fully plausible in its modeling assumptions,...

Source: http://arxiv.org/abs/1012.5649v1

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Sep 20, 2013
09/13

by
R. Aldrovandi; A. L. Barbosa

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Two distinct gauge potentials can have the same field strength, in which case they are said to be ``copies'' of each other. The consequences of this possibility for the general space A of gauge potentials are examined. Any two potentials are connected by a straight line in A, but a straight line going through two copies either contains no other copy or is entirely formed by copies.

Source: http://arxiv.org/abs/math-ph/0410034v1

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Jul 20, 2013
07/13

by
Edilson Vargas; Marcia C. Barbosa

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The phase behavior of a cross-linked polymer blend made of two incompatible species, $A$ and $B$, of different chemical nature is analyzed. Besides a homogeneous phase, this system also exhibits two microphases and a phase of total segregation. The transition between the homogeneous and the microphase is continuous along a $\lambda$-line; a first-order phase boundaries separate the microphase and the disordered phase from the phase of complete segregation. The critical line meets the...

Source: http://arxiv.org/abs/cond-mat/9712211v1

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Jul 20, 2013
07/13

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R. Aldrovandi; A. L. Barbosa

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The geometrical picture of gauge theories must be enlarged when a gauge potential ceases to behave like a connection, as it does in electroweak interactions. When the gauge group has dimension four, the vector space isomorphism between spacetime and the gauge algebra is realized by a tetrad-like field. The object measuring the deviation from a strict bundle structure has the formal behavior of a spacetime connection, of which the deformed gauge field-strength is the torsion. A generalized...

Source: http://arxiv.org/abs/math-ph/0107021v1

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Jun 27, 2018
06/18

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Ezequiel Barbosa; Ben Sharp; Yong Wei

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Let $(M^{n+1},g,e^{-f}d\mu)$ be a complete smooth metric measure space with $2\leq n\leq 6$ and Bakry-\'{E}mery Ricci curvature bounded below by a positive constant. We prove a smooth compactness theorem for the space of complete embedded $f$-minimal hypersurfaces in $M$ with uniform upper bounds on $f$-index and weighted volume. As a corollary, we obtain a smooth compactness theorem for the space of embedded self-shrinkers in $\mathbb{R}^{n+1}$ with $2\leq n\leq 6$. We also prove some...

Topics: Differential Geometry, Analysis of PDEs, Mathematics

Source: http://arxiv.org/abs/1503.01945

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Oct 22, 2014
10/14

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Correia, Luis Claudio Lemos; Barbosa, Carolina Esteves

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This article is from Arquivos brasileiros de cardiologia , volume 102 . Abstract None

Source: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3987398

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Oct 26, 2014
10/14

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Maksud, F.A.N.; Kakehasi, A.M.; Barbosa, A.J.A.

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This article is from Brazilian Journal of Medical and Biological Research , volume 46 . Abstract Obesity is a multifactorial disorder often associated with many important diseases such as diabetes, hypertension and other metabolic syndrome conditions. Argyrophil cells represent almost the total population of endocrine cells of the human gastric mucosa and some reports have described changes of specific types of these cells in patients with obesity and metabolic syndrome. The present study was...

Source: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3854404

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Jun 27, 2018
06/18

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V. S. Barbosa; V. A. Menegatto

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In this paper we study continuous kernels on compact two point homogeneous spaces which are positive definite and zonal (isotropic). Such kernels were characterized by R. Gangolli some forty years ago and are very useful for solving scattered data interpolation problems on the spaces. In the case the space is the $d$-dimensional unit sphere, J. Ziegel showed in 2013 that the radial part of a continuous positive definite and zonal kernel is continuously differentiable up to order $\lfloor...

Topics: Mathematics, Classical Analysis and ODEs

Source: http://arxiv.org/abs/1505.00029

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Jun 27, 2018
06/18

by
V. S. Barbosa; V. A. Menegatto

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We present a necessary and sufficient condition for the strict positive definiteness of a real, continuous, isotropic and positive definite kernel on a two-point compact homogeneous space. The characterization adds to others previously obtained by D. Chen at all (2003) in the case in which the space is a sphere of dimension at least 2 and Menegatto at all (2006) in the case in which the space is the unit circle. As an application, we use the characterization to improve upon a recent result on...

Topics: Functional Analysis, Mathematics

Source: http://arxiv.org/abs/1505.00591

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Oct 25, 2014
10/14

by
Pereira, Maria Amelia Dias; Barbosa, Maria Alves

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This article is from BMC Medical Education , volume 13 . Abstract Background: The undergraduate medical course is a period full of stressors, which may contribute to the high prevalence of mental disorders among students and a decrease in life’s quality. Research shows that interventions during an undergraduate course can reduce stress levels. The aim of this paper is to evaluate the Strategies for Coping with Professional Stress class offered to medical students of the Federal University of...

Source: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3627623

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Jun 28, 2018
06/18

by
Raul Fuentes-Azcatl; Marcia C. Barbosa

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The model Tip4p/{\epsilon} for water is tested for the presence of thermodynamic and dy- namic anomalies. Molecular dynamic simulations for this model were performed and we show that for this system the density versus temperature at constant pressure ex- hibits a maximum. In addition we also show that the diffusion coefficient versus density at constant temperature has a maximum and a minimum. The anomalous behavior of the density and of the diffusion coefficient obey the water hierachy. The...

Topics: Condensed Matter, Soft Condensed Matter

Source: http://arxiv.org/abs/1508.01972

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Jun 28, 2018
06/18

by
Raul Fuentes-Azcatl; Marcia C. Barbosa

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A new computational model for Sodium Chloride, the NaCl/{\epsilon}, is proposed. The Force Fields employed here for the description of the NaCl is based on a set of radial particle-particle pair potentials involving Lennard-Jones (LJ) and Coulombic forces. The parameterization is obtained fitting the density of the crystal and the density and the dielectric constant of the mixture of salt with water at diluted solution. Our model shows good agreement with the experimental values for the density...

Topics: Condensed Matter, Soft Condensed Matter

Source: http://arxiv.org/abs/1508.01971

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Jun 27, 2018
06/18

by
Fernando Barbosa V. da Silva; Fernando Albuquerque Oliveira; Marco Aurélio A. Barbosa

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The thermodynamic and kinetics of the one dimensional lattice gas with repulsive interaction is investigated using transfer matrix technique and Monte Carlo simulations. This simple model is shown to exhibit waterlike anomalies in density, thermal expansion coefficient and self diffusion. An unified description for the thermodynamic anomalies in this model is achieved based on the ground state residual entropy which appears in the model due to mixing entropy in a ground state phase transition.

Topics: Condensed Matter, Soft Condensed Matter, Statistical Mechanics

Source: http://arxiv.org/abs/1503.03007

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Sep 18, 2013
09/13

by
Rodrigo S. C. Leao; Valmir C. Barbosa

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A cycle double cover (CDC) of an undirected graph is a collection of the graph's cycles such that every edge of the graph belongs to exactly two cycles. We describe a constructive method for generating all the cubic graphs that have a 6-CDC (a CDC in which every cycle has length 6). As an application of the method, we prove that all such graphs have a Hamiltonian cycle. A sense of direction is an edge labeling on graphs that follows a globally consistent scheme and is known to considerably...

Source: http://arxiv.org/abs/cs/0505088v4

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Sep 22, 2013
09/13

by
Nandinii Barbosa-Cendejas; Alfredo Herrera-Aguilar

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We consider the generation of thick brane configurations in a pure geometric Weyl integrable 5D space time which constitutes a non-Riemannian generalization of Kaluza-Klein (KK) theory. In this framework, we show how 4D gravity can be localized on a scalar thick brane which does not necessarily respect reflection symmetry, generalizing in this way several previous models based on the Randall-Sundrum (RS) system and avoiding both, the restriction to orbifold geometries and the introduction of...

Source: http://arxiv.org/abs/hep-th/0603184v4

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Sep 19, 2013
09/13

by
G. D. Barbosa; N. Pinto-Neto

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We carry out an investigation into the possibility of developing a Bohmian interpretation based on the continuous motion of point particles for noncommutative quantum mechanics. The conditions for such an interpretation to be consistent are determined, and the implications of its adoption for noncommutativity are discussed. A Bohmian analysis of the noncommutative harmonic oscillator is carried out in detail. By studying the particle motion in the oscillator orbits, we show that small-scale...

Source: http://arxiv.org/abs/hep-th/0304105v5

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Sep 22, 2013
09/13

by
Luciano da Fontoura Costa; Marconi Soares Barbosa

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This paper describes how realistic neuromorphic networks can have their connectivity fully characterized in analytical fashion. By assuming that all neurons have the same shape and are regularly distributed along the two-dimensional orthogonal lattice with parameter $\Delta$, it is possible to obtain the exact number of connections and cycles of any length from the autoconvolution function as well as from the respective spectral density derived from the adjacency matrix. It is shown that...

Source: http://arxiv.org/abs/cond-mat/0310669v1

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Sep 19, 2013
09/13

by
J. G. Bartlett; D. Barbosa; A. Blanchard

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We present an argument for a {\it lower limit} to the Compton-$y$ parameter describing spectral distortions of the cosmic microwave background (CMB). The absence of a detectable Gunn-Peterson signal in the spectra of high redshift quasars demands a high ionization state of the intergalactic medium (IGM). Given an ionizing flux at the lower end of the range indicated by the proximity effect, an IGM representing a significant fraction of the nucleosynthesis-predicted baryon density must be heated...

Source: http://arxiv.org/abs/astro-ph/9506125v1

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Sep 23, 2013
09/13

by
Pierre Delsart; Domingos Barbosa; Alain Blanchard

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Galaxy cluster surveys based on the Sunyaev-Zeldovich effect (SZE) mapping are expected from ongoing experiments. Such surveys are anticipated to provide a significant amount of information relevant to cosmology from the number counts redshift distribution. We carry out an estimation of predicted SZE counts and their redshift distribution taking into account the current cosmological constraints and the X-ray cluster temperature distribution functions. Comparison between local and distant...

Source: http://arxiv.org/abs/1006.3859v2

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Jul 20, 2013
07/13

by
Marcia M. Szortyka; Marcia C. Barbosa

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We investigate the relation between thermodynamic and dynamic properties of an associating lattice gas (ALG) model. The ALG combines a two dimensional lattice gas with particles interacting through a soft core potential and orientational degrees of freedom. From the competition between the directional attractive forces and the soft core potential results two liquid phases, double criticality and density anomaly. We study the mobility of the molecules in this model by calculating the diffusion...

Source: http://arxiv.org/abs/cond-mat/0609551v1

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40

Sep 18, 2013
09/13

by
D. Antypov; M. Barbosa; C. Holm

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We investigate the effect of excluded volume interactions on the electrolyte distribution around a charged macroion. First, we introduce a criterion for determining when hard-core effects should be taken into account beyond standard mean field Poisson-Boltzmann (PB) theory. Next, we demonstrate that several commonly proposed local density functional approaches for excluded volume interactions cannot be used for this purpose. Instead, we employ a non-local excess free energy by using a simple...

Source: http://arxiv.org/abs/cond-mat/0502333v1

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29

Sep 18, 2013
09/13

by
Nandinii Barbosa-Cendejas; Alfredo Herrera-Aguilar

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We present a pair of symmetric formulations of the matter sector of the stationary effective action of heterotic string theory that arises after the toroidal compactification of d dimensions. The first formulation is written in terms of a pair of matrix potentials Z_1 and Z_2 which exhibits a clear symmetry between them and can be used to generate new families of solutions on the basis of either Z_1 or Z_2; the second one is an O(d+1,d+n+1)-invariant formulation which is written in terms of a...

Source: http://arxiv.org/abs/hep-th/0202006v1